Sand tiger sharks are large sharks belonging to the family Odontaspididae, a word which comes from the Greek words odous for ‘teeth’ and aspis for ‘shield’. They are found all over the world, both in oceans and in public aquariums.
1. Sand tiger sharks and tiger sharks are not the same.
Before anything else, let’s get one thing straight – sand tiger sharks are not the same as the tiger shark (Galeocerdo cuvier). In fact, they’re not at all related. Tiger sharks are bigger, have a pattern of spots and stripes, which give them their name, and more rounded snouts. Sand tiger sharks have pointed snouts and have reddish spots on their backs. They get their name from their ferocious appearance as well as the fact that they are often found in sandy bays. Sand tiger sharks can also be found in reefs, shallow waters and in the open ocean up to depths of around 600 feet.
There are four species of sand tiger sharks – the Indian sand tiger shark, the small-toothed sand tiger shark, the large-eyed sand tiger shark and simply the sand tiger shark, the best known of them all.
The sand tiger shark is known by other names, such as the grey nurse shark or blue nurse sand tiger – although it is not related to the nurse shark –the spotted ragged-tooth shark, slender-tooth shark and ground shark.
2. Sand tiger sharks can grow over 10 feet long.
At birth, a sand tiger shark is about three feet long, doubling its length in five to ten years. On average, they can reach a full length of 6.5 to 10.5 feet and weigh between 200 to 350 pounds. As in most sharks, the females are larger because they have to be able to carry their eggs.
3. Sand tiger sharks are the fiercest looking sharks…
The sand tiger shark is a cousin of the great white shark so it looks fearsome, too. In fact, it looks even more fearsome with its three rows of slender, sharply pointed teeth that are often showing because it swims with its mouth open. Even with its mouth closed, though, the dagger-like teeth still protrude, making them look like they are too big for the shark’s mouth. The sand tiger shark has a bulkier body than the great white, too.
Like the great white shark, the sand tiger shark has no eyelids so it looks like it’s always staring. In order to keep its eyes clean or protect them, it simply rolls them back in their sockets. Creepy.
4. …But they have never killed any humans.
In spite of its killer looks, the sand tiger shark has only 29 confirmed attacks on humans since the late 1500s, none of which were fatal. That’s low, considering the great white shark has 314 recorded attacks, 80 of which ended up in someone’s death.
Generally, sand tiger sharks are gentle and have been seen swimming alongside humans. They only become aggressive when food is present, such as when they are being fed or when people are fishing, using their favorite food as bait. They can also become aggressive when scuba divers stick too close to them, especially in big groups, but quickly calm down once the divers back off.
5. Sand tiger sharks can breathe two different ways.
Like all fishes, sharks breathe through their gills and they have two different methods of doing so – buccal pumping and ram ventilation.
Buccal pumping means the shark pulls water into its mouth and then pumps it over its gills using its powerful cheek muscles. Ram ventilation means that as the shark moves forward, it takes in water and rams it through its gills. Ram ventilators need to move constantly in order to breathe, which is why you don’t see great white sharks keeping still.
Sand tiger sharks can breathe either way. They can manually pump water into their gills while they are resting or they can ram water into their gills while swimming. They switch back and forth as needed, breathing in the most efficient way.
6. They are the only sharks that come to the surface to gulp air.
Speaking of breathing, the sand tiger shark is the only shark known to come to the surface to gulp air. But not to breathe. As we mentioned, sand tiger sharks can breathe very well underwater. What then do they use the air for?
Sand tiger sharks store the air in their stomachs, which makes them more buoyant, like an inflated beach ball. In this way, they can float above the ocean floor without moving, silently looking for prey.
Like all other sharks, sand tiger sharks are excellent hunters. They eat mostly fish, including skates, rays and smaller sharks, sharks up to half their size. Small prey are swallowed whole while larger ones are broken down into smaller chunks before they are eaten.
7. The battle for the fittest sand tiger shark begins in the mother’s womb.
Like many sharks, female sand tiger sharks are ovoviviparous, which means eggs develop inside their bodies, hatch there, continue to develop and then are born as live young called pups. Whereas most sharks give birth to a lot of pups, though, female sand tiger sharks only give birth to two pups once every two to three years, making their reproductive rates one of the lowest among fishes.
There is a story behind this. The female sand tiger shark actually starts out with a lot of eggs, up to 50 in each uterus but the first to hatch eats the rest that have not yet hatched, one at a time. Even when they do hatch, they are small so the largest one eats them until it is the only one remaining, by which time it has grown big enough to be born. The female gives birth to the two pups – one from each uterus – and swims away without a backward glance. After all, the pups have already proven that they can survive. This is called intrauterine cannibalism or adelphophagy, which literally means ‘eating one’s brother’.
8. Sand tiger sharks migrate each year.
Sand tiger sharks are found in the world’s major oceans and seas, as far east as India, as far north as Japan and as far south as Australia. Every year, many of them migrate to warmer waters during the winter in order to mate. Afterwards, the females migrate to even warmer winters to spend the rest of their pregnancy. Then in the summer, they return to cool waters where the females give birth to their pups. Only the adults migrate. The juveniles simply move deeper into the ocean during winter.
9. They do well in captivity.
Many large sharks are impossible to be kept in captivity but sand tiger sharks do surprisingly well, which is why you’re likely to see one the next time you visit a marine park. In fact, it is a popular attraction in public aquariums because of its menacing appearance and yet relatively docile behavior.
You still can’t keep one at home, though, because you’ll need a large tank. (Remember, it can grow over ten feet.) And because you need to feed it a lot of live fish. Also, although they survive, sand tiger sharks tend to get spinal deformities in captivity, making them look hunched.
Sand tiger sharks in captivity have been known to live for up to 16 years.
10. Sadly, sand tiger sharks are currently vulnerable to extinction.
Now, this isn’t a fun fact. Currently, the sand tiger shark is listed as Vulnerable by the IUCN, which means its population has declined by at least 20% in the past ten years. Why?
There are several threats to the sand tiger shark’s population, including fishing for its meat, liver oil and fins. It is also hunted for sport and caught in beach nets and trawls. Unfortunately, because of its migration patterns, which means the sand tiger shark appears at certain places at certain times of the year, it has been easy to catch.
Since laws have been put in place, less sand tiger sharks have been caught but its population is still slow to recover because of its low reproductive rate.
Sand Tiger Shark Videos
The YouTube video below contains a playlist of 4 videos looking at sand tiger sharks.
The first clip may not be suitable be for very young viewers – parental discretion is needed.
A list and brief description of videos featured is below.
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More Shark Video Pages to Enjoy:
Tiger Sharks, Bull Sharks, Hammerhead, Mako, Great White, Megamouth, Goblin Sharks, Shark Senses, Sharks and Humans, Tonic Immobility, Whale Sharks, Lanternshark, Megalodon, Cookiecutter, Frilled Sharks, Spiny Dogfish, Basking Sharks, Angel Shark, Horn Sharks, Wobbegong, Zebra Shark, Blue Sharks, Nurse Sharks, Reef Sharks, Sand Tiger Shark, Oceanic Whitetip.